This commit makes LLVM not estimate branch probabilities when doing a
single bit bitmask tests.
The code that originally made me discover this is:
if ((a & 0x1) == 0x1) {
..
}
In this case we don't actually have any branch probability information
and should not assume to have any. LLVM transforms this into:
%and = and i32 %a, 1
%tobool = icmp eq i32 %and, 0
So, in this case, the result of a bitwise and is compared against 0,
but nevertheless, we should not assume to have probability
information.
CodeGen/ARM/2013-10-11-select-stalls.ll started failing because the
changed probabilities changed the results of
ARMBaseInstrInfo::isProfitableToIfCvt() and led to an Ifcvt of the
diamond in the test. AFAICT, the test was never meant to test this and
thus changing the test input slightly to not change the probabilities
seems like the best way to preserve the meaning of the test.
llvm-svn: 234979
Remove all the global bits to do with preserving use-list order by
moving the `cl::opt`s to the individual tools that want them. There's a
minor functionality change to `libLTO`, in that you can't send in
`-preserve-bc-uselistorder=false`, but making that bit settable (if it's
worth doing) should be through explicit LTO API.
As a drive-by fix, I removed some includes of `UseListOrder.h` that were
made unnecessary by recent commits.
llvm-svn: 234973
Pull the `-preserve-ll-uselistorder` bit up through all the callers of
`Module::print()`. I converted callers of `operator<<` to
`Module::print()` where necessary to pull the bit through.
llvm-svn: 234968
For consistency, start pulling out `-preserve-ll-uselistorder`. I'll
drop the global state for both eventually. This pulls it up to
`Module::print()` (but not past there).
llvm-svn: 234966
Change the callers of `WriteToBitcodeFile()` to pass `true` or
`shouldPreserveBitcodeUseListOrder()` explicitly. I left the callers
that want to send `false` alone.
I'll keep pushing the bit higher until hopefully I can delete the global
`cl::opt` entirely.
llvm-svn: 234957
Canonicalize access to whether to preserve use-list order in bitcode on
a `bool` stored in `ValueEnumerator`. Next step, expose this as a
`bool` through `WriteBitcodeToFile()`.
llvm-svn: 234956
Now we don't have to do 2 synchronized passes to compute offsets and then
write the file.
This also includes a fix for the corner case of seeking in /dev/null. It
is not an error, but on some systems (Linux) the returned offset is
always 0. An error is signaled by returning -1. This is checked by
the existing tests now that "clang -o /dev/null ..." seeks.
llvm-svn: 234952
Inlining such intrinsics is very difficult, since you need to
simultaneously transform many calls to llvm.framerecover and potentially
duplicate the functions containing them. Normally this intrinsic isn't
added until EH preparation, which is part of the backend pass pipeline
after inlining. However, if it were to get fed through the inliner,
this change will ensure that it doesn't break the code.
llvm-svn: 234937
Summary:
There are a number of passes that could be sped up by using dominator tree DFS numbers to order or compare things across multiple bbs
(MemorySSA, MergedLoadStoreMotion, EarlyCSE, Sinking, GVN, NewGVN, for starters :P).
For example, GVN/CSE elimination can be done with a simple stack/etc (instead of full-on scoped hash table or repeated leader set walks)
if the DFS pair is stored next to leaders.
The dominator tree keeps them, and the DOM tree nodes expose them as public, but you have no guarantee they are up to date (and in fact,
if you split blocks or whatever during your pass, they definitely won't be)
This means passes either have to compute their own versions[1], or make 32 queries, or ....
Rather than try to hide this, i just made the API public, and make it do nothing if the numbers are already valid.
[1] Which we want as a non-recursive walk, which is not pretty, sadly,
because it cannot use the depth first iterators since you don't get called on the way back up. So you either have to do one walk with po_iterator
and one with df_iterator, or write your own non-recursive walk that looks identical to the one in updateDFSNumbers.
Reviewers: chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8946
llvm-svn: 234930
Change all the normally relevant output in `verify-uselistorder` from
using `dbgs()` to using `outs()` and `errs()`. Now you don't need
`-debug=uselistorder` to figure out what's going on (or at what stage
verification failed, or to get the paths of the left-behind temporary
files). This is a debugging tool, so I put the logging messages on
`outs()` and the error messages on `errs()`.
I also adjusted the output to be less ***loud***. Not sure why I was so
`*`-happy when I first wrote this.
llvm-svn: 234929
This causes badness for GDB which expects to find a definition in any
compile_unit that has an entry for the variable in its pubnames.
llvm-svn: 234915
I'd added some stuff to this test case without adding the original
source, which makes updating/adding further stuff rather difficult. So
update it first (& it seems in the interim Clang's changed its output
order a bit, so adjust the CHECK lines to account for that - rather than
hand hacking the IR order which just makes it harder to maintain/change
next time)
llvm-svn: 234911
Certain versions of CMake specify /W3 as part of CMAKE_CXX_FLAGS
by default, before you do anything. Appending /W4 to the end of
this and using the Ninja generator results in
cl : Command line warning D9025 : overriding '/W3' with '/W4'.
It is not possible to suppress this since it is a command line
warning and not a compiler warning, so we must fix the command
line to contain only one value for /Wn.
llvm-svn: 234907
As a follow-up to r234850, add an implicit conversion from
`DISubprogram` to `DIScope` to support Kaleidoscope Ch. 8. This also
reverts that band-aid from r234890.
(/me learns *again* to build Kaleidoscope before commit...)
llvm-svn: 234904
With commit r219944, InstCombine can now turn a sqrtl into a llvm.fabs.f64.
The call graph edge originally representing the call to sqrtl becomes invalid.
This patch modifies CGPassManager::RefreshCallGraph() to remove the invalid
call graph edge, which can triggers an assert in
CallGraphNode::addCalledFunction().
Phabricator Review: http://reviews.llvm.org/D7705
Patch by Lawrence Hu <lawrence@codeaurora.org>.
llvm-svn: 234902
if ((a & 0x1) == 0x1) {
..
}
In this case we don't actually have any branch probability information and
should not assume to have any. LLVM transforms this into:
%and = and i32 %a, 1
%tobool = icmp eq i32 %and, 0
So, in this case, the result of a bitwise and is compared against 0,
but nevertheless, we should not assume to have probability
information.
llvm-svn: 234898
The ARMv8 ARMARM states that for these instructions in A64 state:
"Unspecified bits in "imm5" are ignored but should be set to zero by an assembler.", (imm4 for INS).
Make the disassembler accept any encoding with these ignored bits set to 1.
llvm-svn: 234896
This pass will always try to insert llvm.SI.ifbreak intrinsics
in the same block that its conditional value is computed in. This is
a problem when conditions for breaks or continue are computed outside
of the loop, because the llvm.SI.ifbreak intrinsic ends up being inserted
outside of the loop.
This patch fixes this problem by inserting the llvm.SI.ifbreak
intrinsics in the loop header when the condition is computed outside
the loop.
llvm-svn: 234891
Summary:
Without this check the following case failed:
Skip a SubBlock which is not a MODULE_BLOCK_ID nor a BLOCKINFO_BLOCK_ID
Got to end of file
TheModule would still be == nullptr, and we would subsequentially fail
when materializing the Module (assert at the start of
BitcodeReader::MaterializeModule).
Bug found with AFL.
Reviewers: dexonsmith, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9014
llvm-svn: 234887
Some targets (ie. Mips) have additional rules for ordering the relocation
table entries. Allow them to override generic sortRelocs(), which sorts
entries by Offset.
Then override this function for Mips, to emit HI16 and GOT16 relocations
against the local symbol in pair with the corresponding LO16 relocation.
Patch by Vladimir Stefanovic.
Differential Revision: http://reviews.llvm.org/D7414
llvm-svn: 234883
TargetRegisterInfo::getRegPressureLimit has a note that it is an old
model that relies on manually entered classes. Using the newer model of
register pressure sets seems more appropriate. We might eventually even
switch to lib/CodeGen/RegisterPressure.cpp, but we should probably do
incremental changes here.
Using the newer model also makes it easier to take regmasks into account
which is necessary to fix llvm.org/PR23143. I am currently also
preparing a patch for that, but would like to do this switch
independently.
Review: http://reviews.llvm.org/D8986
llvm-svn: 234880
The testcase that is included in the patch caused a crash when doing DebugInfoFinder::processModule
on the module due to DCT->getElements() returning nullptr in DebugInfoFinder::processType.
By doing "DCT->getElements()" instead of "DCT->getElements()->operands()" one gets a DIArray
instead of a raw MDTuple. The former has code to handle null as a 0-element array and
therefore avoids the crash.
Differential Revision: http://reviews.llvm.org/D9008
llvm-svn: 234875
Summary:
This transformation reassociates a n-ary add so that the add can partially reuse
existing instructions. For example, this pass can simplify
void foo(int a, int b) {
bar(a + b);
bar((a + 2) + b);
}
to
void foo(int a, int b) {
int t = a + b;
bar(t);
bar(t + 2);
}
saving one add instruction.
Fixes PR22357 (https://llvm.org/bugs/show_bug.cgi?id=22357).
Test Plan: nary-add.ll
Reviewers: broune, dberlin, hfinkel, meheff, sanjoy, atrick
Reviewed By: sanjoy, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8950
llvm-svn: 234855
